Does caffeine shampoo stop hair loss?

The trial against minoxidil

In a 2017 trial at five centres in India, 210 men with androgenetic alopecia applied either a 0.2% caffeine liquid or 5% minoxidil twice a day for six months. The proportion of hairs in the growing phase rose by about 11 percentage points in both groups, and the authors concluded caffeine was not inferior. There was no placebo group, so the trial cannot show that either beat doing nothing, and neither patients nor examiners were blinded. Dr Kurt Wolff funded it, and two of the authors worked for or consulted for the company. The product tested was a liquid left on the scalp, not a shampoo.

What the advertising regulator ruled

In March 2018 the UK Advertising Standards Authority upheld a complaint against an Alpecin advert. It found the Indian trial "non-blinded", said it "did not relate to the product being advertised", and noted that twice-daily use did not reflect how people use a shampoo. It concluded it had seen no well-conducted study of the actual product on people's scalps, so the claim "it can actually help to reduce hair loss" was misleading.

The shampoo trials

A 2025 double-blind trial in 154 men found fewer hairs came out in a pull test after six months with a shampoo than with a placebo shampoo. Dr Kurt Wolff funded it, two authors worked for the company and a third for its sister company, Dr August Wolff, and the shampoo contained a second active ingredient besides caffeine, so the result cannot be put down to caffeine. A 2025 systematic review of nine caffeine trials rated the evidence medium in three, low in one and very low in five.

What dermatology guidelines say

A 2025 Canadian consensus of 11 physicians put caffeine, and shampoos and lotions containing fermented papaya, fermented mangosteen and caffeine, among the 17 of 45 treatments it does not recommend. The European S3 guideline, whose literature search ended in 2015, found no caffeine study that met its inclusion criteria, and made no recommendation for or against.

Where the idea comes from

The case for caffeine started in the laboratory. In a 2007 study, hair follicles taken from scalp biopsies and grown in dishes grew more when caffeine was added, and caffeine offset the slowing effect of testosterone. That shows what caffeine does to a follicle in a dish, not whether a shampoo rinsed off after a few minutes regrows hair.

Sources

1. An Open-Label Randomized Multicenter Study Assessing the Noninferiority of a Caffeine-Based Topical Liquid 0.2% versus Minoxidil 5% Solution in Male Androgenetic Alopecia · Skin Pharmacology and Physiology, 2017 · PMID 29055953
2. ASA Ruling on Dr Kurt Wolff GmbH & Co KG t/a Alpecin (A17-387365) · Advertising Standards Authority, 2018
3. A Novel Approach Against Male Pattern Hair Loss With Topical Dimethylglycine Sodium Salt (DMG-Na) and Caffeine: Efficacy of a 24-Week, Double-Blind, Randomized, Placebo-Controlled Trial · Journal of Cosmetic Dermatology, 2025 · PMID 40820949
4. Caffeine as an Active Ingredient in Cosmetic Preparations Against Hair Loss: A Systematic Review of Available Clinical Evidence · Healthcare, 2025 · PMID 39997270
5. A Canadian Consensus on Androgenetic Alopecia: Approach and Management · Journal of Cutaneous Medicine and Surgery, 2025 · PMID 40986632
6. Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men – short version · Journal of the European Academy of Dermatology and Venereology, 2018 · PMID 29178529
7. Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro · International Journal of Dermatology, 2007 · PMID 17214716